Surveillance helped stop plots against NYSE and New York subway, official says

The National Security Agency surveillance programs made public this month have helped foil more than 50 terrorist plots since Sept. 11, including one to blow up the New York Stock Exchange, top intelligence officials told Congress.

The officials appeared before the House Intelligence Committee and answered mostly friendly questions to defend the programs, which collect phone records inside the United States and monitor Internet communications overseas. “I would much rather be here today debating this point than trying to explain how we failed to prevent another 9/11,” said Gen. Keith Alexander, the NSA director. At least 10 of the foiled plots were “homeland-based threats,” he said. Alexander said he would provide details of all the foiled plots to the committee in secret.